﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Engine.Dtd.Schema {
    /// <summary>
    /// Defines the different constraints on an attribute's presence on an element.
    /// </summary>
    public enum DAttributePresence {
        /// <summary>
        /// The attribute has a default value, and its presence is optional.
        /// </summary>
        Default,
        /// <summary>
        /// The attribute has a fixed value, if present.
        /// </summary>
        Fixed,
        /// <summary>
        /// The attribute must always be present on every element.
        /// </summary>
        Required,
        /// <summary>
        /// The element is optional.
        /// </summary>
        Implied
        }
    }
